Undoubtedly, this tome contains some canonical stories about the secrets of the Fortress of Solitude. We see the Fortress's first appearance in Superman #17; then we get three stories where Superman flashbacks to reexamine the history of the Fortress, its previous locations, and importance of several items in the Fortress while the Fortress was in danger, or the source of threat to humanity (Fortress of Fear). Later we have an interesting issue about Krypton's past (Memories of Krypton's Past) albeit it isn't about the Fortress, and in my opinion, the best story in this collection. Finally, we have a story of the reconstruction of the Fortress by Superman and Steel. However, I felt that other issues were missing that could have been important to this collection. For example, there is a Superman issue that shows the first time the Fortress is located in the Arctic, there is the issue where the Fortress is destroyed, not to mention that the Fortress has changed to other locations. In sum, considering the importance of the Fortress to the Superman myth, I felt the volume deserved an omnibus treatment rather than these 200 pages. The book also lacks any introduction about the Fortress, making references to different issues where the Fortress is important. For the above reasons, I do not consider this tome important for a collector, or non collector. I give it three stars because the stories are fun and entertaining, they do talk about the Secrets of the Fortress, they explain why this citadel is important to Superman, and they are offered in full color. Nevertheless, it falls short from "I liked it" because I felt that it was a half-hearted gesture from DC publishers.
In addition, considering the brief treatment on this subject, a Superman fan may be better off getting these stories from the Chronicles, the different Showcase editions, and recent graphic novels from the post-nineties period.
Note: I had read the above review before purchasing this book and thought it twice because of the warning on the pages that were upside down. It may have been some error at the printing house because my edition did not contain this error. I have no complaints as to the publishing quality.